Caloric restriction under the guise of weight-loss herbs

Confused about supplements?

Two updates this week, both relatively moderate in depth and importance. The first, Kothala Himbutu (Salacia reticulata) is an up-and-coming anti-diabetic weightloss herb that we are nipping in the bud before amazing claims get attributed to it, and African Melon (Irvingia gabonensis) is one of the few supplements that has rose to popularity on the Dr.Oz train; it is the least popular of the trifecta of African Melon, Raspberry Ketones, and Green Coffee Extract (Chlorogenic Acid), all of which have unnecessary amounts of popularity.

For starters, Salacia reticulata does indeed appear promising. At least one rat study has noted an increase in metabolic rate as measured by indirect calorimetry, but it did not quantify the increase; although it isn't false to say it increases metabolic rate, the evidence doesn't seem too solid as it is just one study. Additionally, there are some interactions at the level of the fat cell where it may reduce triglyceride uptake and proliferation but aside from not being too potent it is not known which bioactive does this. A lack of pharmacokinetic data also precedes any conclusions we can make on how well the in vitro data translates.

The most notable benefit of Salacia is the ability to prevent carbohydrate uptake (quite potently, with many compounds in Salacia being potent) and to a lesser degree fat absorption (not overly potent). Unfortunately, fecal analysis has not been conducted on rats so it is unsure how potent it is in vivo. Salacia definitely causes weight loss in both lean and obese mice, it isn't wholly known why, but it is suspected to just prevent carbohydrate uptake; a caloric restriction in disguise.

Irvingia gabonensis is similar to a caloric restriction in disguise, but its mechanism of action appears to be through appetite suppression. Similar to glucomannan (a highly viscous dietary fiber that can turn soup into jello), Irvingia is a liquid thickener that can work in the body and slow down intestinal transit speed and suppress the rate of food absorption and increase satiety from that. Similar to Salacia, Irvingia appears to have some in vitro evidence suggesting that it might confer some additional benefits beyond reducing food intake but the practical significance is currently unknown. The benefits to lipid metabolism in particular appear quite astonishing, but for unknown reasons; the studies are also quite small in size, so it would be prudent not to put too much faith into the degree of lipid reduction.

In the end, these two herbs may have some promise as clever ways to induce a caloric deficit but their benefits may wholly dependent on consuming less calories (and thus negated if overconsuming food, or mimicked by just not eating).